Heredity And Evolution - MCQ Test (22-11-2017) - Class 10 MCQ

Wings of bird and wings of insect both are analogous as both of them perform the same function of flight while structures and origin are different. Feathers of birds originate from their forelimbs, the wings of insects originate from the inner or outer surface of the insect’s body.

The billions of human beings living today all belong to one species: Homo sapiens. As in all species, there is variation among individual human beings, from size and shape to skin tone and eye color. But we are much more alike than we are different.

DNA isolation is a process of purification of DNA from sample using a combination of physical and chemical methods. The first isolation of DNA was done in 1869 by Friedrich Miescher.

Hormones, proteins and enzymes are the result of specific gene sequences and different type of hormones, proteins and enzymes are secreted by varying gene codings.
Fats are combination of fatty acids and glycerol and is completely not a gene based secretion.

The carriers of factor (genes) are chromosomes and transfer hereditary information from one generation to another.

Gregor Mendel is called the father of genetics because he was the first person in the world to observe the fact that characteristics were passed on from the parents to the children.

August Weismann (1834-1914) was a neo-Darwinian biologist who proposed the germplasm theory in his book Das Keimplasma.
He said that variations are of two types. Some are congenital i.e., organisms are born with them. Others are acquired during the life time of a particular plant or animal. It was with this latter type of variations, the acquired characters, that Weismann was very much concerned. He gradually developed his Theory of Germplasm to explain that acquired characters could not be inherited.

Gregor John Mendel is considered as father of genetics as he laid down the principles or laws of inheritance for the first time. Though his works were based on plants but the laws governing inheritance patterns are also applicable to humans and hence we call them as “ Mendel's Laws of Inheritance”.

Mendel selected pisum sativum (a pea plant )of his ground to observe the characterstics of progeny produced.

Since roundness and yellow colour are shown by capital letters in the genotype so they are dominant traits. We know that only dominant traits are expressed in F1 generation.

Eukaryotic chromosome typically contains 2 copies of each gene and is therefore genetically diploid. The diploid eukaryotic genome is halved to haploid via the process called meiosis.

Genetics is the study of genes, genetic variation, and heredity in living organisms. It is generally considered a field of biology, but intersects frequently with many other life sciences and is strongly linked with the study of information systems.

Archaeopteryx had a full set of teeth and three claws on the wing which had been used to grasp prey.

The genotype  is the part (DNA sequence) of the genetic makeup of a cell, and therefore of an organism or individual, which determines a specific characteristic  of that cell/organism/individual.

Hugo de Vries in his book Die Mutation Theory (1901) proposed the mutation theory in order to explain the mechanism of evolution.
This theory was based on his observations on evening primrose, Oenothera lamarckiana. He studied this plant in wild forms for many years continuously and observed certain spontaneous changes in some of these wild plants. These plants differed considerably in stem height, flower colour and leaves shapes. He observed that these changes were heritable and ultimately led to several new varieties.

Mendel selected seven pairs of contrasting characters.  Plant Height,Pod Shape,Pod Color,Seed Shape,Seed Color and Flower Position.So flower shape and pod position not included here.

The use and disuse of an organ by an organism leads to acquiring ‘variation’ in the features of that organ’ was proposed by Jean Baptist Lamarck.
Individual efforts during the lifetime of the organisms drive species to adaptation, as they supposedly would acquire adaptive changes and pass them on to offspring i.e.., by selective use and disuse of an organ, organisms acquire or loose certain traits during their lifetime.

As during fertilisation, sperm only gives nucleus, but ova gives nucleus as well as cytoplasm. Therefore, the mitochondrial DNA and other cytoplasmic factors are inherited directly from mother. there are some traits which are exclusively linked with Y- chromosome and they are inherited by the male child directly from father.

A GMO (genetically modified organism) is the result of a laboratory process where genes from the DNA of one species are extracted and artificially forced into the genes of an unrelated plant or animal. The foreign genes may come from bacteria, viruses, insects, animals or even humans.

Charles Darwin listed a number of putative human vestigial features, which he termed rudimentary, in The Descent of Man (1890). These included the muscles of the ear, wisdom teeth, the appendix, the tail bone, body hair, and the semilunar fold in the corner of the eye.

Wings of parrot and wings of a housefly perform the function of flying. But the parrot’s wings are originated from the mesoderm and are supported by bones while the housefly’s wings are ectodermal in origin are supported by the chitinous structures.

Karyotype is the number and appearance of chromosomes in a nucleus of somatic cell. Somatic cells are diploid cells which make up the body. They have two sets of chromosomes. So, if an egg cell (gamete cell) which is a haploid cell (with single set of chromosomes)has 10 chromosome, then number of chromosomes present in a somatic cell will be 20 chromosomes . As egg cells are produced by female body, then among 20 chromosomes, two X chromosomes will be sex chromosome. So, karyotpe of that animals will be showing 18 autosomes.

Punnett's gametic checkerboard method is of great use in deducting the genotype and phenotype of the F2 offsprings of a hybridization cross. The gametic checkerboard has the equal number of squares in horizontal and vertical lines according to the number of gametic combinations of F1 hybrid.

This statement is correct that chromosomes are bearers of hereditary units or genes and each chromosome carries hundreds or thousands of genes.

Charles Darwin was a British naturalist who proposed the theory of biological evolution by natural selection. Darwin defined evolution as "descent with modification," the idea that species change over time, give rise to new species, and share a common ancestor. The mechanism that Darwin proposed for evolution is natural selection. Because resources are limited in nature, organisms with heritable traits that favor survival and reproduction will tend to leave more offspring than their peers, causing the traits to increase in frequency over generations.

Backcrossing is a crossing of a hybrid with one of its parents or an individual genetically similar to its parent, in order to achieve offspring with a genetic identity which is closer to that of the parent. It is used in horticulture, animal breeding and in production of gene knockout organisms.

Branch of study which deals with the fossils is called as paleontology.It deals with the study of the life of past geological periods as known from fossil remains.

An egg or sperm only has half of the parent's sex chromosome pair. An egg will always have an X chromosome, since the woman's sex chromosome pair only has Xs. Sperm can have either an X chromosome or a Y chromosome.
If a sperm with an X chromosome fertilizes the egg, the new cell will have two X chromosomes. One came from the father's sperm and one came from the mother's egg. Since the sex chromosome that is made is XX, the cell will grow into a girl baby.

Paleontologists view Archaeopteryx as a transitional fossil between dinosaurs and modern birds. With its blend of avian and reptilian features, it was long viewed as the earliest known bird. Discovered in 1860 in Germany, it's sometimes referred to as Urvogel, the German word for "original bird" or "first bird." Recent discoveries, however, have displaced Archaeopteryx from its lofty title.

Variations that result from factors such as climate, food supply and actions of other organisms are called as somatic (phenotypic) variations. These variations are not due to differences in genes or chromosomes, and in general are not transmitted future generations. They do not have any significance in the process of evolution.