Earth Science

sexual reproduction

sexual reproduction

involves the union of male and female gametes/sex cells, in the process of fertilization that results in the development of a new organism

asexual reproduction

does not involve gametes but uses modified plant organs such as stems, leaves, or roots

rhizomes

modified stems that grow underground; grow horizontally in different directions

tubers

thickened ends of rhizomes

bulbs

round, modified underground buds covered with bulb scales that are modified leaves

corms or bulbo-tubers

short, vertical, swollen underground plant stems that serve as a storage organs of some plants such as taro

runners or stolons

horizontal stems that grow above the ground

suckers

similar to stolons but develop from roots

flowers

sexual structures of angiosperms

stamen

(male reproductive organ) found inside the petals, each having a filament

pistil

female reproductive organ

sepals

outermost and resemble leaves in a round configuration; cover and protect the developing shoot, and are collectively known as calyx

petals

broad, flat, and thick but greatly differ in size, shape, and color

anther

where the pollen grains are formed. each pollen grain contains two cells surrounded by a tough outer wall

carpels

comprise pistil, a.k.a pistil

stigma

acts as the receptacle for the pollen grains

style

hollow structure where the pollen tube develops

ovary

contains one or more ovules (the female gametes)

pollination

process where pollen grains from the anther reach the stigma of pistil

self-pollination

reproductive process that occurs when pollination is done within

cross-pollination

involves another individual

embryo

develops as the seed matures

embryonic plant

has a short root or radicle. it also has a shoot, hypocotyl, and a single pair of cotyledons (the embryonic leaves)

cotyledon

serves as food storage for the plant embryo since it is still not able to perform photosynthesis

clone

offspring produced through asexual reproduction

binary fission

the body of unicellular parent divides into two equal parts through mitosis and produces an offspring that develops similarly as the parent

multiple fission

involves repeated division of nucleus prior to the cytoplasm which ends up producing many daughter cells

budding

unequal division of an organism’s body where a new individual arise as an outgrowth or bud from its parent that then detaches and becomes separate individual

gemmule formation

when an aggregation of cells surrounded by a resistant capsule is used to form a new individual

fragmentation

when an animal breaks into two or more parts, with each fragment capable of forming into a new individual

biparental

production of offspring upon the union of gametes from genetically distinct parents. the offspring would have a combination of genes from each parent but are genetically distint from the parents

ovary

female gonad which produces ova (singular: ovum) or egg cells

accessory organs

penis, vagina, and uterus

dioecious or gonochoristic

animals that have separate and female individuals

monoecious

those who have both male and female reproductive systems present in a single individual

gene

comes from the greek term “descent“ and was coined by wilhelm johanssen in 1909 for the hereditary factors as described by gregor mendel - the father of modern genetics

replication

happens when cells undergo mitotic division, when each daughter cell must have an exact copy of the DNA of the parent cell

messenger rna

serves as the intermediary molecule between DNA and protein

codon

sequence of bases present in MRNA molecule