Free Heredity and Evolution 01 Practice Test - 10th Grade
Question 1
Variations that affect germ cells are termed as somatic variations.
SOLUTION
Solution : B
Varations that occur in the somatic cells are known as somatic variations. They are variation that are not passed on from one generation to another generation. Germinal variations are the variations that take place in the germ cells. These variations are inherited by the future generations.
Question 2
Set of observable characteristics in an organism is called phenotype.
SOLUTION
Solution : A
∙ Set of observable characteristics in an organism is known as phenotype.
∙ An organism's phenotype is the morphological representation of its genotype.
∙ Few examples of phenotype are: Eye colour in humans, height in humans, flower colours in plants, height of plants, etc.
Question 3
The diagram below shows undisturbed sedimentary strata at the bottom of an ocean. The fossils found in layer B resemble the fossils found in layer A. This similarity suggests that
The fossils in layer B were formed before the fossils in layer A
Modern forms of life may have evolved from earlier forms of life
Vertebrate fossils are only found in sediments
The fossils in layer A must be more complex than those in layer B
SOLUTION
Solution : B
Speciation is the formation of new species from the pre-existing ones. Since the fossils are found in different layers of sedimentary rock, It is evident that older layer contains older species and the newer layers contain newer species. The newer species are formed by changes or modifications in the older species. Thus, the similarities of fossils suggests the evolution of new species from the pre-existing ones.
Question 4
According to fossil discovered up to present time, the origin and evolution of man started from _______ .
France
Java
Africa
China
SOLUTION
Solution : C
According to fossils discovered up to present time, the origin and evolution of man started from Africa. Regardless of where we have lived for the past few thousand years, we all come from Africa. The earliest members of the human species, Homo sapiens, can be traced there. Even our genetic footprints can be traced back to our African roots. According to various models and theories, modern humans originated in Africa and started to disperse through the world roughly 50,000 to 100,000 years ago. Such theories are based on the human fossil timeline records.
Question 5
A male gamete with X chromosome fuses with a female gamete to form a zygote. The eventual offspring will be a male child.
SOLUTION
Solution : B
A male gamete with an X chromosome, when it fuses with a female egg which always has an X chromosome, the offspring will have an XX chromosome pair. This means the eventual offspring will be a female child. Sex determination in humans is based on XX-XY system where XX means female XY means male.
Question 6
The technique of establishing evolutionary relationships based on changes accumulated in the DNA is known as _______ .
SOLUTION
Solution : C
Molecular phylogeny is the technique that employs comparison of changes accumulated in the DNA of an organism over generations to establish evolutionary relationships. This approach is based on the idea that organisms which are more distantly related will accumulate a greater number of differences in their DNA.
Question 7
Human cells have ______ pair(s) of autosomes.
SOLUTION
Solution : C
Humans have a total of 23 pairs of chromosomes, out of which 22 pairs are autosomes and 1 pair has sex chromosomes.
∙ The members of the autosomal pairs are homologous i.e., they are similar in shape and organisation.
∙ On the other hand, sex chomosomes or allosomes may be heterologous (in males) or homologous (in females).
Question 8
Gene flow between the two populations of beetles separated by the river is maximum.
SOLUTION
Solution : B
The two populations of the beetles are separated by a river, due to which the migration between the two communities is limited, but not restricted. Due to this, there is only a minimum possibility gene flow between the two populations.
Question 9
Which of the following are characteristics of analogous organs?
SOLUTION
Solution : A and D
Analogous organs are those which serve similar function but do not share similar structure and origin. A common example of analogous organs is wings of butterfly and a bird. Both are used for flying, but neither their structures are similar nor they originate from a common ancestor.
Question 10
In evolutionary terms, we have more in common with a ________ .
SOLUTION
Solution : C
Humans did not evolve from monkeys. Humans are more closely related to modern apes than to monkeys, but we didn't evolve from apes either. There existed a common ancestor for both the chimpanzees and humans, about 5-8 million years ago. Later, the two lineages diverged into two separate lineages. One of these lineages ultimately evolved into chimps and other apes, and the other evolved into early human ancestors called hominids.