chp 7 Flashcards
nucleus
In biology, the structure in a cell that contains the chromosomes
chromosome
long threads of DNA found in the nucleus of a cell
DNA
a chemical made up of long molecules in a twisted ladder shape known as a double helix.
gene
part of the chromosomes that determine features of an organism
gamete
sex cells; two gametes fuse together to produce a zygote
zygote
a fertilized egg cell from a female gamete fusing with a male gamete
beginning of new life
how many chromosomes are there in a cell
46 chromosomes
23 pairs of chromosomes
what are the different gametes called and list some differences between them
sperm cell = male
sperm can move smaller
egg cell= female
egg stationery bigger contains food reserves.
what determines the gender of a baby
a sperm can either contain a x chro or a y chro, a egg always contains a x chro. if an egg is fertilized by a x containing sperm it will be a girl since it has two x’s. if an egg is fertilized by a sperm containing y chro it will be a boy because it has only one x.
sex inheritance
the way in wich the x and y chromosomes are inheartated
natural selection
the increased chance of survival of individuals that have particular features these individuals, therefore, have a greater chance of survival and passing on their genes to the next generation
natural selection marks
individuals in species show variation
individuals in a species compete for recorces
only individuals best adapted to survive
only survivors will pas on their genes
suggest how the increased temp in the environment effects the ability of humans to reproduce
in order to reproduce you need to have both male and female gametes. So if the temp of the environment increases and damages the male gametes (sperm), it is not possible to reproduce and there is a decreased chance of fertilization as the sperm is damaged.
