Chromosomes Genes And Dna Flashcards
What can you use to see chromosomes cell dividing?
A light microscope
How many chromosomes do humans have?
46 chromosomes
Name the two gametes
The female gamete
The male gamete
What are the male gametes and where are they produced
Sperm cells are the male gametes and they are very small cells produced in the testes
What are the female gametes and where are they produced?
Egg cells are the female gametes and they are small ells produced in the ovaries but they are bigger than the sperm cells
How is semen produced?
Sperm cells travel from the testes to the vagina mixed with the gland fluid producing semen.
How does the semen reach the uterus?
During sexual intercourse semen is ejaculated, reaches the cervix and reaches the uterus
When does fertilisation occur?
Fertilization occurs when sperm cells nucleus fuses with egg cells nucleus forming a zygote the egg cell membrane, hardens preventing sperm from entering
How many chromosomes does each gamete have?
Each gamete has 23 chromosomes
What is the information found in the nucleus of every cell arranged into chromosomes.
It is DNA or also known as Deoxyribonucleic acid
How many pairs of chromosomes do humans have?
23
What joins our body together to form proteins that make our body perform the way it needs?
Amino acids
How can genetic conditions be passed down?
Either through generations or can be cause by lifestyle factors such as smoking, contact with radioactive substances we call these factors mutagens
What are mutagens?
Mutagens have the ability to change the DNA code which can cause the cell to start making the wrong proteins and carrying out the wrong functions.
Name 3 genetic conditions
Dwarfism
Down syndrome
Cystic fibrosis
What does sickle cell anaemia do to the body?
In sickle cell anaemia it changes the shape of the red blood cell.
What is the 23rd pair chromosome made up from?
It is made up of the X and Y chromosomes. It differs in males and females
How many x chromosomes does a female have?
Two
What type of chroosome does a male have?
A male has and X and Y chromosome
When a sperm cell and egg cell fuse together at fertilisation the new cell that is produced is called a?
A zygote
What is the shape of a DNA molecule?
Double helix
What is a gene?
A segment of DNA in a chromosome responsible for a particular function.
What happens to the nucleus of the sperm cell at fertilisation
During fertilisation the nucleus of the sperm cell fuses with the nucleus of the egg cell to form a new cell called a zygote
State two reasons why the egg cell is much bigger than the sperm cell.
The surface area of the egg cell increases the chance of fertilisation at it is a bigger target.
The large cell allows more space for the cytoplasm where all the nutrients for the embryo is stored
