Science - Chapter 5: Grade 7

sex chromosomes

One of the 23 pairs of chromosomes in the human, contains genes that will determine the sex of the individual.

sex-linked genes

Genes located on the sex chromosomes. Their alleles are passed from parent to child on a sex chromosome

carrier

a person who has one recessive allele for a trait and one dominant allele

Genetic disorder

An abnormal condition that a person inherits through genes or chromosomes

Pedigree

A chart or "family tree" that tracks which members of a family have a particular trait

Karyotype

a picture of all the chromosomes in a person's cell

Selective breeding

The process of selecting a few organisms with desired traits to serve as parents of the next generation

inbreeding

involves crossing two individuals that have similar desirable characteristics

Hybridization

crossing two genetically different individuals

clone

an organism that has exactly the same genes as the organism from which it was produced

genetic engineering

genes from one organism are transferred into the DNA of another organism

gene therapy

inserting copies of a gene directly into a person's cells

Why can we study dog genes to study human diseases?

The mutation in our genes only happens to one gene in dogs

concerns with genetic engineering

people think that genetically engineered crops may not be safe. They fear these crops may harm the environment or cause health problems in humans.

Help for people with genetic disorders

Medical care, education, and job training

Punnet square

cystic fibrosis

A genetic disorder in which the body produces abnormally thick mucus in the lungs and intestines

sickle cell disease

Caused by a mutation that affects hemoglobin. The red blood cells of people with this disease have a sickle or crescent shape. The sickle-shape blood cells can’t carry as much oxygen as normal cells

Hemophilia

a genetic disorder in which a person's blood clots very slowly or not at all

Down syndrome

a person's cells have an extra copy of chromosome 21

Why is hemophilia more common in males?

It is a sex-linked disorder, and the trait is on the x chromosome

Using a stem cutting from an African violet, it’s easy to produce a plant, which is a…

Clone