This document contains definitions of key biology and genetics terms provided by a student named Beverley Sutton from Pistor Middle School. The definitions are simplified explanations intended for other students to understand. Some terms defined include adaptation, allele, asexual reproduction, cell, cell division, chromosome, DNA, dominant, evolve, gene, genotype, heterozygous, inherit, migrate, natural selection, offspring, phenotype, punnett square, recessive, sexual reproduction, species, and symbiosis.

1. Beverley Sutton
Pistor Middle School

2.  Definition - the changes in behavior, physiology, and
structure of an organism to become more suited to the
environment.
 My definition – something special about you that helps
you fit your environment better.

4.  Allele - the different forms of a gene
 My definition – the different types of genes you get
from your parent (Example: hair color)

5.  Asexual Reproduction – non-sexual reproduction;
reproduction which produces offspring from one
parent that is genetically identical to the parent ( a
clone).
 My definition – getting a baby from just one parent

6.  Cell - the basic unit of structure and function in living
things
 My definition – the tiny building blocks of organisms

7.  Cell Division - the process by which a cell divides to form
two daughter cells
 My definition – the way a cell copies itself
Cell divides into two identical daughter cells

9.  Chromosome - The
physical structures in cells
containing the large
stretches of DNA (hundreds
of millions of bases) and the
information for thousands of
genes. Humans have 22 pairs
of chromosomes plus the
pair of sex chromosomes
(XX or XY) - 23 pairs in all -
i.e. 46 chromosomes.
 My definition – tightly
wound DNA

10.  Co-dominance - A condition in which the alleles of a gene
pair in a heterozygote are fully expressed thereby resulting
in offspring with a phenotype that is neither dominant nor
recessive .
 My definition – a mixture of two strong alleles

11.  Diversity - The number and variety of species present
in an area
 My definition – lots of differences in all the organisms
living in one place

12.  DNA -
Deoxyribonucleic acid;
the genetic material
that carries information
about an organism and
is passed from parent to
offspring
 My definition – the
spiral ladder molecule
that is the blueprint for
all life on Earth.

13.  Dominant - An allele or a gene that is expressed in an
organism’s phenotype, masking the effect of the
recessive allele or gene when present (strongest).
 My definition – the strongest gene (the bully in the
playground)

14.  Dormant - (behavioral/physiological adaptation) an
organism whose growth and activity has stopped.
 My definition – sleeping … suspended animation

16.  Evolve - to
change over
time
 My definition
– to change
very slowly
from
generation to
generation.
How we get
different
species.

17.  Charles Darwin, developed his Theory
of Descent with Modification … now
known as the Theory of Natural
Selection.
 Individuals in any species have
differences (variations). These
variations could give an individual the
ability to survive longer and breed,
ensuring that this beneficial (helpful)
variation would be passed to the
survivor’s offspring, slowly resulting in
new species over a long period of time.

18.  Jean Baptiste Lamarck was another 19th
century scientist who also tried to
explain evolution with his Theory of
Acquired Characteristics. Lamarck
thought that animals using, or not using,
physical features caused those changes
to be passed to their offspring. He
believed that creatures went from less
complex to more complex and viewed
evolution like a ladder.

19. Organisms can
NOT choose to
evolve

22.  Gene - The set of
information that
controls a trait; a
segment of DNA on a
chromosome that
codes for a particular
trait.
 My definition – a
piece of DNA (a
“sentence” in the
DNA “book”)

23.  Genetic adaptation: the natural selection of the offspring
better adapted to a new environment.
 My definition – something special about your DNA that
helps you fit your environment better.

24.  the two alleles for an inherited
trait; one from each parent
(E.g. TT, tT, Tt, or tt)
 Genotypes are always written
as pairs and are by convention
written as a combination of
the upper and lowercase
version of the same letter as
shown above.
 Exceptions: XX and XY (the
sex genotypes), and also the
blood type genotypes.

25.  Heterozygous -- having
two different alleles for
a single trait
(AKA Hybrid)
Homozygous -- having
identical alleles for a
single trait (AKA Purebred)

26.  having a related or similar
position, structure, etc.
Similar in structure and
evolutionary origin, though
not necessarily in function,
such as the flippers of a
seal and the hands of a
human.
 Similar structure, similar
position, same origin.

27.  Hibernate - (behavioral/physiological adaptation) an
organism enters a state of greatly reduced body activity
during winter
 My definition – a very deep winter sleep that allows an
animal to survive months without food

28.  Inherit - to acquire genetic traits from a parent
 My definition – to be born with characteristics from a
parent

29.  Incomplete dominance - A kind of dominance occurring
in heterozygotes (two DIFFERENT alleles) in which the
dominant allele is only partially expressed, and usually
resulting in an offspring with an intermediate phenotype.
 My definition – a blended mixture of two different alleles

30.  Migrate - (behavioral adaptation) - an organism
moves to a new location and back again. Usually for
feeding and reproduction.
 My definition – to move to where the food is, or to
move to the place to have babies

31.  Mutate (Mutation) – 1. A
sudden structural change
within a gene or
chromosome of an
organism resulting in the
creation of a new
characteristic or trait not
found in the parental type.
2. A permanent change in
the genetic material that
may alter a trait or
characteristic of an
individual, or manifest as
disease, and can be
transmitted to offspring.

32.  Natural Selection - a natural process resulting in the
evolution of organisms best suited (adapted) to an
environment
 My definition – the way good mutations spread to help
you better suit your environment

33.  Offspring - The progeny or descendants of a person,
animal, or plant considered as a group.
 My definition – babies!

34.  the way the genotype is expressed (shows) in the
individual (E.g. Blue or Orange tail; Brown or blonde
hair).
 My definition: the characteristics you can see or
measure (E.g. blood type)

35.  Punnett Square - is a diagram that is used to predict
an outcome of a particular cross or breeding
experiment
 My definition – heredity tic-tac-toe!
 Remember rows then columns or columns then rows
… don’t try to wing it!

37.  Recessive - hidden or masked. Recessive allele – an allele
that is masked when a dominant allele is present.
 My definition – shy, hides, only shows when the bully isn’t
around!

38.  Sexual Reproduction - the union of two sex cells (male &
female) which produces a unique organism that shows a
combination of genetic traits from both parents.
 My definition – reproduction that needs a male and female
parent

39.  Species– a distinct group whose members can
interbreed
 My definition – a group of the same type.

40.  Symbiosis - a close relationship between two
organisms of different species that benefits at least one
of the organisms.
 My definition – two organisms that live together and it
helps at least one of them.

41.  Vary - to change. Variation: in genetics, a change in
characteristics in an individual from the group to
which it belongs, or deviation in characteristics of the
offspring from those of its parents.

42.  Refers to a body part that has become small and lost its
original use because of evolutionary change.
 Shrunken body part, no longer used