Males have two dissimilar chromosomes X and Y/heterogametic;
Females have two similar chromosomes X and X/homogametic;
Male gamete/sperms have either X or Y chromosome, while all ova have X chromosome;
If a sperm with X fuses with an ovum a female is formed and if a sperm with Y fuses with an ovum a make is formed;
Sickle-cell trait is heterozygous while sickle cell anaemia is a homozygous condition;
People with sickle cell trait are resistant to malaria; because the plasmodium cannot survive in sickle shaped cells.
adhixbelly answered the question on September 20, 2017 at 09:40
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(a) Describe the mechanism of gaseous exchange in plants through the lenticels. (b) Explain each of the following:the tracheoles lack spiral bands of chitin;the floor of the mouth...
(Solved)
(a) Describe the mechanism of gaseous exchange in plants through the lenticels. (b) Explain each of the following:the tracheoles lack spiral bands of chitin;the floor of the mouth...
Date posted:
September 20, 2017
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Answers (1)
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(a) State four characteristics of fruits dispersed by animals. (b) State two roles of each of the following hormones in menstruation:l (i) luteinising hormone (ii) oestrogen.
(Solved)
(a) State four characteristics of fruits dispersed by animals. (b) State two roles of each of the following hormones in menstruation: (i) luteinising hormone (ii) oestrogen.
Date posted:
September 20, 2017
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Why is a burning charcoal stove in a poorly ventilated room likely to cause death of the inhabitants?
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Why is a burning charcoal stove in a poorly ventilated room likely to cause death of the inhabitants?
Date posted:
September 20, 2017
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Name three types of transpiration
Date posted:
September 19, 2017
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a)What is meant by seed dormancy? (b)state three causes of seed dormancy?
Date posted:
September 19, 2017
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Outline types staining process
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September 18, 2017
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What is Biology?
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September 18, 2017
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What is a gene?
Date posted:
September 18, 2017
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What type of membrane is the cell membrane in terms of permeability?
Date posted:
September 18, 2017
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What is the name of an RNA sequence that codifies one amino acid?
Date posted:
September 18, 2017
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(Solved)
Where does respiration take place in a cell?
Date posted:
September 18, 2017
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(Solved)
State the adaptations of plants which enable them to reduce water loss
Date posted:
September 18, 2017
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Answers (1)
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(Solved)
State the structural differences between xylem vessels and sieve tubes
Date posted:
September 18, 2017
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Explain the environmental factors that affect rate of transpiration in plants
(Solved)
Explain the environmental factors that affect rate of transpiration in plants
Date posted:
September 18, 2017
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Explain the structural factors that affect the rate of transpiration in plants
(Solved)
Explain the structural factors that affect the rate of transpiration in plants
Date posted:
September 18, 2017
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(Solved)
Explain the uptake of mineral salts by plants
Date posted:
September 18, 2017
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(Solved)
Explain the forces that make water and mineral salts move through a plant
Date posted:
September 18, 2017
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(Solved)
Describe the movement of water from the soil to the leaves of a tall plant
Date posted:
September 18, 2017
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Why do flowering plants need water?
Date posted:
September 18, 2017
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(Solved)
State the role of vitamin K to the human body
Date posted:
September 16, 2017
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Answers (1)