Biology: Reproduction

Reproduction

• The purpose of reproduction is to create offspring.

Types of Reproduction

• Asexual reproduction occurs when an organism can reproduce on its own, without gametes.
• Sexual reproduction involves gametes to produce offspring.
• Fertilization is the union of egg and sperm.
• Ovulation is when a matured egg/ovum is released.

Asexual Reproduction

• This process does not involve gametes; instead, parts of a mature organism develop into new individuals.
• Offspring are genetically identical to the parent.

Types of Asexual Reproduction

• Binary Fission is the separation of the body into two new bodies, common in single-celled organisms like bacteria.
• Fragmentation involves the parent body breaking into pieces, each growing into a new individual.
• Vegetative Reproduction uses plant parts like stems, leaves, roots, or turions to reproduce new plants.
• Budding involves a new organism developing as an outgrowth (bud) from the parent body, eventually detaching.

Animal Reproduction

• Male reproductive organs are the Testes.
• Seminiferous tubules produce sperm through spermatogenesis.
• Reproduction is regulated by GnRH, FSH, and LH hormones.
• The development of ovarian follicles is termed Oogenesis, which occurs in the ovaries.
• Estrogen and progesterone are secreted from the ovaries.
• Fertilization happens in the fallopian tubes (oviducts).
• The uterus (womb) consists of the endometrium and myometrium.

Animal Development Stages

• Gametogenesis is listed as the first stage.
• Fertilization follows gametogenesis.
• Implantation is listed as the third stage.
• Gastrulation Is stage number 4.
• Embryonic Stage involves the formation of 4 membranes, placenta development, and organ formation.
• Fetal Stage is when organs further differentiate and grow.

Hormonal Regulation of Animal Reproduction

• Gonadotrophin releasing hormones (GnRH) stimulate the release of Luteinizing Hormone (LH) and Follicle Stimulating Hormone (FSH).
• Follicle Stimulating Hormone (FSH) in males causes the testes to produce sperm.
• Follicle Stimulating Hormone (FSH) in females causes growth of ovarian follicle cells, secreting estrogen.
• Luteinizing Hormone (LH) in males causes the testes to secrete testosterone.
• Luteinizing Hormone (LH) in females causes ovulation and the secretion of progesterone.
• The pituitary gland secretes two gonadotropic hormones.

Plant Reproduction

• The stamen makes up the male portion of a flower.
• The stamen consists of an anther and a filament.
• The anther produces haploid pollen grains via meiosis.
• Most flowers contain multiple stamens.
• The carpel/pistil makes up the structure of the female portion of a flower.
• The stigma is sticky, and its role is to trap pollen.
• The style is a hollow tube connecting the stigma and ovary.
• The ovary produces female gametes (ovules).

Plants and Animals Nutrition

• Nutrients help living organisms develop, grow, heal and provide energy
• Autotrophic Nutrition involves organisms producing their own food.
• Heterotrophic Nutrition involves organisms depending on other sources of food.

Digestion

• Digestion involves the mechanical and chemical breakdown of complex food substances into simpler, smaller pieces.

Parts of the Digestive System

• The mouth produces saliva, where mechanical mastication forms a bolus.
• The esophagus is a muscular tube that conducts peristalsis, serving as a passageway for food.
• The stomach is a muscular sac containing gastric juices to chemically break down food.
• The liver produces bile to help with fat digestion.
• The gall bladder stores bile and discharges it into the cystic duct.
• The pancreas releases pancreatic juices and enzymes to help digest protein and starch.
• The small intestine absorbs nutrients and water coming from food.
• The large intestine absorbs water and salts from undigested material and eliminates waste.
• The anus is an opening that eliminates feces from the body.
• The epiglottis prevents fluids and food from entering the respiratory system.

Digestive Processes

• Ingestion is taking in food materials.
• Digestion is the breakdown of food into smaller pieces.
• Absorption is the movement of nutrients, water, and electrolytes from the small intestine into cells, then into the blood.
• Elimination is when undigested material passes out of the system.