O-LevelBiologyGenetics & Variation5090/22 · Oct/Nov 2019 · Q910 Marks
Following sexual intercourse in humans, fertilisation may take place.
- (a)Describe the process of fertilisation and the early development of a ball of cells.[4]
- (b)The ball of cells may then become implanted in the wall of the uterus and form a developing fetus. Describe how a developing fetus obtains and uses the named substances it needs and removes its named waste products.[6]
Mark scheme
Marking points from the official mark scheme (Oct/Nov 2019). The mark or mark type is shown in brackets.
- [4] gamete(s); egg(s) / ovum / ova + sperm ; fuse / join / combine AW ; zygote ; cell division; mitosis; embryo / blastula / blastocyst / morula ;
- [6] oxygen + respiration; glucose + respiration; amino acids + protein synthesis / growth / cell division ; ions / vitamins / minerals / salts / antibodies + for named use; removal AW of + carbon dioxide / urea ; placenta ; umbilical cord ; diffusion; capillaries; mother's blood + fetus' AW blood;
Write your answer and get it marked
On Oracle Prep you can write or photograph your own answer and have it marked by AI against this mark scheme, with feedback on what you missed.
Sign up free →