Topic 2 Part 4 - Reproduction Flashcards
How do prokaryotic cells divide?
Prokaryotic cells divide (reproduce) asexually by the process of binary fission and this results in reproduction of the parent cell into identical progeny cells.
Species that reproduce sexually have individuals that differ from each other, whereas asexual reproduction leads to identical individuals within a population. What do you think are the advantages for a species of reproducing sexually in comparison with asexually?
If all individuals in a population are identical they will respond in a similar manner to any external influence. The external influence could be, for example, lack of a food source, how attractive they are to a predator, or susceptibility to a particular catastrophic disease. In any of these three examples the entire population could be wiped out and the species could become extinct. In comparison, species that reproduce sexually will have individuals that differ from each other, which means that the species could respond to external influences differently and have better chances of survival.
What changes can you observe in the pictures of a human evolving over time?
There are a number of changes you could have observed including an increase in height, a more upright posture, changes to the skull or face to become less ‘ape-like’, and wearing clothes.
What do all living cells need to survive?
Oxygen
What shape does sickle cell anaemia cause the red blood cells to become?
Rigid and ‘crescent-shaped’ or ‘sickle-like’
How is sickle cell anaemia passed on?
It is hereditary which means it is passed down the generations from parents to offspring
What can having sickle cell anaemia protect the sufferer from getting?
Malaria
What causes malaria?
Malaria is caused by a parasite carried by the Anopheles mosquito
What is the name of the malarial parasite mosquitos carry?
Plasmodium falciparum, in its saliva
What is sickle cell a good example of in Darwin’s theory?
Survival of the fittest
What is a gamete?
a mature haploid male or female germ cell which is able to unite with another of the opposite sex in sexual reproduction to form a zygote.
What is a zygote?
a diploid cell resulting from the fusion of two haploid gametes; a fertilized ovum.
What are gamete in humans?
Gametes in humans are sperm or egg cells.
What does mitosis ensure in terms of chromosomes?
It ensures that each progeny cell contains chromosomes that are exact copies of those of the parent cell in every respect.
What is meiosis?
is a process where a single cell divides twice to produce four cells containing half the original amount of genetic information
