Biology
Given below are two stages in the evolution of man. Study them and answer the questions that follow:
(i) Identify Australopithecus and Neanderthal man from the above pictures.
(ii) Mention two characteristic features each for the two stages.
(iii) Who proposed the theory of 'Natural Selection'?
(iv) Name the organism used as an example to explain 'Industrial Melanisum'.
(v) Give two examples of vestigial organs in humans.
Answer
(i) Picture A → Neanderthal man, Picture B → Australopithecus.
(ii) Two characteristic features of each are:
- Neanderthal man — Height 160 cm, semi erect stooping posture, Cranial capacity 1450 cm3
- Australopithecus — Height 120 cm, nearly upright posture, Cranial capacity 450 to 600 cm3
(iii) The theory of 'Natural Selection' was proposed by Charles Darwin.
(iv) Peppered moth (Biston bitularia) was the organism used as an example to explain 'Industrial Melanisum'.
(v) Two examples of vestigial organs in humans are:
- Vermiform Appendix
- Wisdom tooth
Related Questions
Given alongside is an apparatus which was set up to investigate a physiological process in plants. The setup was placed in bright sunlight. Answer the questions that follow :
(i) Name the process being studied. Define the process.
(ii) Why was the pot enclosed in a rubber sheet?
(iii) Mention two external factors which can accelerate the above process.
(iv) List two adaptations in plants to reduce the above process.
(v) Draw a neat, labelled diagram of a stomatal apparatus.
The diagram given below represents an endocrine gland in the human body. Study the diagram and answer the following questions :
(i) Identify the endocrine gland. Where is it located?
(ii) Why is the above gland referred to as the 'Master gland'?
(iii) Name the hormone which in deficiency causes Diabetes Insipidus. How does this disorder differ from Diabetes Mellitus ?
(iv) Explain the term 'Hormone'. What is the role of Tropic hormones in the human body?
(v) Which lobe of the above gland secretes:
- Oxytocin
- ACTH
- Growth hormone
Given below is a diagram representing a stage during the mitotic cell division. Study the diagram and answer the following questions :
(i) Identify the stage by giving a suitable reason.
(ii) Is it a plant or an animal cell? Give a reason to support your answer.
(iii) Draw a neat, labelled diagram of the stage which follows the one shown in the diagram.
(iv) How many chromosomes will each daughter cell have after the completion of the above division ?
(v) Name the four nitrogenous bases.
In Mendel's experiments, tall pea plants (T) are dominant over dwarf pea plants (t).
(i) What is the phenotype and genotype of the F1 generation if a homozygous tall plant is crossed with a homozygous dwarf plant?
(ii) Draw a Punnett square board to show the gametes and offspring when both the parents are heterozygous for tallness.
(iii) What is the Phenotypic ratio and genotypic ratio of the above cross in (ii)?
(iv) State Mendel's Law of Dominance.
(v) What is a Dihybrid Cross?